The invention relates to a contact spring for a plug connector socket intended for arrangement and mounting in an insulating body on the one hand and for soldering, in the form of surface mount technology (SMT), to a printed circuit board on the other hand, wherein the contact spring comprises two contact arms which are provided for clamping in and making contact with a mating contact which can be inserted in an insertion direction, and wherein the contact arms are each arranged, starting with a source area and ending with a free standing end area, essentially pointing in the opposite direction to the insertion direction of the mating contact, and first of all running toward one another, and curve away from one another on their free standing end areas, wherein the contact spring furthermore comprises a bridge via which the two contact arms are connected to one another at their respective source areas, and wherein the contact spring comprises at least one first solder connection with at least one contact surface for soldering on the printed circuit board.
In this case, “pointing essentially in the opposite direction to the insertion direction of the mating contact” means that the contact spring is opened in the opposite direction to its insertion direction, in order to hold the mating contact to be inserted, on the free standing end areas of the contact arms.
A contact spring such as this is required in order in particular to fit plug connector sockets using SMT to both sides of printed circuit boards.